Lock parts and method of forming them



April I2, 1938. A. SCHUYLER ET AL LOCK PARTS AND METHOD OF FORMING THEM Fil e d June 14, 1935 FIG.

INVENTORS A. L. \S'CHUYLER A. R. MAGLAGA/V ATTORNEY Patented Apr. 12, 1938 UNITED STATES PATENT OFFICE LOCK PARTS AND METHOD OF FORLIING THEM Application June 14, 1935, Serial No. 26,598 '1 Claims. (01. 29-148) This invention relates to lock parts and a method of forming them, and more particularly to tumblers for rotor center tumbler type locks used in telephone pay stations and a method of mani i ufacturing them.

In locks for telephone pay stations, of the type shown in the patent to O. A. Shann No. 1,793,254, patented February 1'7, 1931, movable and fixed tumblers are provided. The movable tumblers 10- in this type of lock must be moved about a pivot through predetermined distances to bring their "code notches into alignment and to position where a projecting portion of the bolt may pass into the aligned notches. It has been found that if the portion of the tumblers which pass into the notches or slots of a key are made thinner and the slots or notches are-made narrower, the lock is harder to open with an improper key. However, the portion of the tumblers which will a be engaged by the projecting portion of the bolt when an attempt is made to operate the lock with an improper key must be of sufflcient thickness to prevent the bolt from being withdrawn.

It is an object of this invention to provide a a simple and inexpensive tumbler for locks and an 7 economical method of manufacturing it.

In accordance with one embodiment, it is proposed to provide a tumbler having a pivot hole, and code and safety notches perforated therein,

80 a spring rigidly gripped in a toothed slot perforated in the tumbler and a semi-circular depression swaged in the tumbler at one edge thereof to cooperate with the slots or notches in the edge of a key. In accordance with the invention 35 such a 'tumbler is formed by perforating the toothed slot and pivot hole in a strip of sheet metal stock and cutting away a portion of the strip, swaging a portion of the stock adjacent the cutaway portion and knurling or serrating a sur- 40 face of the tumbler, cutting a blank tumbler from that area of the strip which includes the swaged portion, pivot hole and toothed slot, and staking a spring in the toothed slot and cutting the code and safety notches in the tumbler.

A better understanding of the invention will be had from the following detailed description when taken in conjunction with the accompanying drawing, wherein m Fig. 1 is a plan view of a section of sheet metal strip illustrating the first step of the improved method of forming tumblers;

Fig. 2 is another view of the same strip illustrating another step in the method contemplated 6| by the invention;

Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2;

Fig. 4 is a plan view of a blank in the third'step of its formation into a tumbler;

Fig. 5 is a plan view of the tumbler shown in 5 Fig. 4 after the final forming operation and assembly therewith of the spring, and

Fig. 6 is a plan view of a rotor center tumbler type lock with a tumbler formed according to the method illustrated inFigs. 1 to 5 assembled there- 10 circular aperture 9 and a toothed slot l0 having cooperating gripping surfaces 55 have been perforated. The circular aperture 9 will serve in the finally formed tumbler which is indicated by dot and'dash lines H (Figs. 1 and 2) as a pivot hole which will cooperate with a pivot pin l2 (Fig. 6) in a lock. The toothed slot ill will in the completed tumbler receive and clamp a spring l3. The portion 8 of the sheet metal stock I is preliminarily cut from the sheet at the same time that the slot l0 and aperture 9 are punched there- 5 The portion 8 of the strip is removed so that in the next succeeding operation as illustrated in Figs. 2 and 3, the material from the stock will be able to flow away from the formed portion of the tumbler as indicated by the dot and dash lines when a swa-ging operation is performed'thereon.

In the step illustrated in Figs. 2 and 3, the stock is swaged at 14 to reduce the thickness of the stock as shown in Fig. 3. This will tend to force some of the metal from the stock to the position as shown by the uneven line at l5. Simultaneously with the swaging of the lower portion (Figs. 2 and 3) of the sheet metal stock, a knurled or serrated pattern as. indicated at It is embossed on the 40 surface of the stock in the area roughly included by the outline of the part being formed. The serrations or knurling is embossed on the stock to minimize possibility of the stock curling due to the swaging operation.

After the sheet metal strip has been perforated, slotted, swaged and embossed with the design as shown in Fig. 2, a blank ll, of the configuration shown in Fig. 4,.which it will be noted conforms to the outlines as shown in Figs. 1 and 2, 5.0 will be punched from the blank and sheared or shaved along its lower edge as shown by the dot and dash line at the bottom of Fig. 2 and solid line of Fig. 4 to form the blank 11 to substantially its final outline.

7 ing or serrating the surface of the strip and After-the blank I! has been formed to the shape shown in Fig. 4, a spring I3 is positioned in the slot l0 and concurrently a code notch l8 and a safety notch l9 are cut in the blank' IT bya punch press 'operation which simultaneously ring-stakes the spring I3 in the slot I0 as indicated at 20 and embosses a code number as indicated at 2| by the digit 4".

After a tumbler has been formed in accordance with the steps outlined hereinbefore, it may be assembled as shown in Fig. 6 in a lock indicated generally by the numeral 22 wherein it is pivoted about a pin or rivet i2 and urged by its spring l3 to rotate in an-anti-clockwise direction about said pin or rivet I2 and wherein the reduced portion It may cooperate with a key to rotate the tumbler about its pivot I2 until, if the proper key is used, the tumbler or tumblers of the lock will have moved in an arcuate path to permit a lug 23 on a lock bolt 24 to move under the actuation of the barrel or center 25 into the code notch I8.

A tumbler of the type disclosed hereinbefore and manufactured by the method disclosed hereinbefore may be used in looks of the types shown in the patent to O. A. Shann, No. 1,793,254, patented February 17, 1931.

What is claimed is:

1. In a lock, a tumbler having a circular aperture therein for pivotally supporting the tumbler in the look, a code notch and. a safety notch cut in the tumbler, a pair of cooperating gripping surfaces for receiving a spring, and a reduced portion of metal hardened by swaging.

2. In a lock, a tumbler having a circular aperture therein for pivotally supporting the tumbler in the look, a code notch and a safety notch cut in the tumbler, a pair of cooperating gripping surfaces, a reduced portion of metal hardened by swaging, and a tumbler spring held in place between said gripping surfaces by ring-staking the metal of the tumbler into gripping engagement with the spring. a

3. A method of forming tumblers for rotor center tumbler type locks comprising punching a circular aperture and a toothed slot in astrip of metal, forming an edge of the strip of metal to a predetermined contour, simultaneously knurlknurled, positioning a spring in the toothed slot,

and concurrently ring-staking the spring in place and cutting a plurality of notches in the blank.

4. A method of forming tumblers for rotor center tumbler type locks comprising punching a circular aperture and a toothed slot in a strip of metal, forming an edge of the strip of metal to a predetermined contour conforming at one portion of the configuration of the finally formed tumbler, simultaneously knurling or serrating the surface of the strip and swaging a semi-circular depression along the edge formed to a predetermined contour, punching a blank from the strip within the area swaged and knurled, positioning a spring in the toothed slot, and concurrently ring-staking the spring in place and cutting a plurality of notches in the blank.

5. A method of forming tumblers for rotor center tumbler type locks comprising simultaneously punching a circular aperture. a toothed aperture and an irregularly shaped segment from a strip of sheet metal stock, simultaneously swaging an edge of the sheet metal stock adjacent the place where said irregularly shaped segment was punched out and serrating or knurling the surface of said strip to flatten it, punching a blank from the strip within the area swaged and. serrated or knurled, and simultaneously cutting a code notch anda safety notch in the blank and ring-staking a spring in the toothed slot.

6. A method of forming tumblers for rotor center tumbler type locks comprising punching a circularaperture, and a toothed slot in a strip of metal, forming an edge of the strip of metal to a predetermined contour, swaging a semi-circular depression along the edge formed to a predetermined contour, punching a blank from the strip within the area swaged and knurled, positioning aspring in the toothed slot, and concurrently ring-staking the spring in place and cutting a plurality of notches in the blank.

7. A method of forming tumblers for rotor center tumbler type locks comprising punching a circular aperture in a strip of metal, forming an edge of the strip of metal to a predetermined contour, simultaneously knurling or serrating the surface of the stripand swaging a semi-circular depression along the edge formed to a predetermined contour, punching a blank from the strip within the area swaged and-knurled, and cutting a plurality of notches in the blank.

ANDREW L. scmnznsza. ALLAN R. MACLAGAN. 

